of akron



April 13 1926. Q

E.. D. PUTT ROTARY CUTTER AND METHOD OF MAKING CUTTER DRUMS Filed March 18, 1924 2 Sheets-Sheet i April 13 192.6: 1,580,918

E. D. PUTT ROTARY CUTTER AND METHOD OF MAKING CUTTER DRUMS Filed March 18, 1924 2 Sheets-Sheet 2 "w i I Patented Apr. 13, 1926.

UNITED STATES.

PATENT OFFICE.

EDWARD D. PUTT, 0F. AKRON, OHIO, ASSIGNOR TO THE FIRESTONE TIRE AND RUBBER COMPANY, OF AKRON, OHIO, A CORPORATION OF OHIO.

ROTARY CUTTER AND METHOD OF MAKING CUTTER DRUMS.

Application filed Mai-ch18, 1924. Serial No. 700,063.

To all whom it may concern:

Be it known that I, EDW'ARD D. Pug-r, a citizen of the United States, and a resident of Akron, county of Summit, State of Ohio,

5 have invented certain new and useful Improvements in Rotary Cutters and Methods of Making Cutter Drums, of which the following is a specification.

This invention relates to rotary cutters 10 and to the art of making cutter drums. In

particular, the invention is directed toward the construction of a cutter drum on which a flexible knife is supported and against which is urged an abutment roll, for pressing the material to be out againstthe knife.

Heretofore, flexible knives have been mounted on drums by securing means, such as screws, inserted through closely spaced perforations in the knives and screwed into the surfaces of the drums. This construction of cutters is highly disadvantageous, especially in that breakage of the knives frequently occurs and'replacements are made only with great difliculty. Furthermore, considerable time is required to so secure a number of such knives on the surface of a drum.

The chief object of this invention are to provide an improved cutter drum construe tion, without the above disadvantages in which a cutter element or wire is held on the surface of the drum by means coacting with the wire only adjacent its ends and to provide a method of making the above described cutter drum.

I have discovered that the chief cause of breakage of cutter wires secured on. the drum of a rotary cutter is the crowding of the material of the knife by the abutment roll progressively from the leading end of the wire, that is the end first contacting, the abutment roll, toward the trailing end thereof, the wire, being prevented from movement by positive retaining means secured to the drum, is accordingly buckled in advance of the retaining means under the pressure of the abutment roll.

Accordingly it is the purpose-of my invention to provide a. structure whereby the flexible knife is positively held at its leading end and is so retained on the drum at the other end as to permit longitudinal movement or displacement of the wire with respect to the surface of the drum.

By experiment, I have found that if the wire is given a preliminary half-twist prior to mounting it on the drum and preferably before it is hardened or tempered it will tend to hug the surface of the drum when wound helically about the latter. My invention, therefore, also comprehends an improved method of forming a cutter drum.

Other objects of my invention will become apparent from the following detailed description in connection with the accompanying drawings in which my invention is shown in its preferred form, it being understood that I do not wholly limit my claims to the specific structure shown and described.

Of the accompanying drawings:

Fig. 1, is a side elevation of a rotary cutter embodying my invention.

Fig. 2, 1s a plan thereof. F 1g. 3, 1s a detail plan illustrating the manner of securing the leading end of a flexijournaled a cutter drum lo which has secured. thereon in a manner later to be described. a series'of elongate, flexible knives 16, 1t: helically wound about the drum 15. For driving the drum 1:). a worm gear 17 is secured thereto and meshes with a worm 18 journaled in the brackets 19, 19 secured to the side of bracket 11. The worm 18 is driven by a sprocket 20 over which is trained a drive. chain 21, the chain 21 being also trained over a sprocket 22 on the shaft 23 of a motor 24 supported on the base plate 10. For leading fabric or the like to the cutter roll thereis provided a roller 25 journaled in brackets 26, 26, which are mounted on the bearing brackets 13 and 14, and a second smaller roller 27, also journaled in brackets 13 and 14. The rollers 25 and 27 cooperating to direct fabric, denoted 28, onto the cutter drum 15 as illustrated in Fig. 1.

screws 55 55, the latter however,

It is preferred to press the material 28 against the knives by a resiliently mounted abutment 'roll 29 and to this end the roll 29 is journaled in bearings 30, 30 formed in slidable brackets 31, 31 mounted on a plat- I 38 on the shafts, providing yielding pressure for the roll 29.

A roller 39 is rotatiyely mounted in arms 40, 40 integral with airadjustable carrier 41, the carrier 41 being suitably mounted on the platform 32. r The roller 39 is adapted to bear against and take up any spring in the roll 29. Accordingl it is adapted to be adjusted toward and rom the surface of roll 29 by hand wheel 42, the shaft 43 of which is threaded into a nut 44 carried by the slide 41. A spring 45 is arranged about the shaft 43 and bears against a collar 46 on the shaft, providing a yielding pressure for the roll 39.

For receiving and removing the cut strips, there is provided a conveyor belt 47-, which is trained over a roller 48 journaled in the bracket members 33, and over a second roller 49 journaled in brackets 50, 50 supported on the platform 32, the belt 47 being so led into contact with the cutter drum 15 as to engage with a substantial portion of the periphery thereof. It is understood that a liner may be substituted for the conveyor belt 47. The roller 48 may be driven in any suitable manner as by chain and sprocket arrangement 48 driven by a worm gear 48 meshing with the worm 18.

As illustrated in Figs. 3 and 4 the leading end of each knife 16, which preferably is a square wire as shown, is clamped in a heli cal V-shaped groove 51 formed in the surface of the drum. While I have shown the wires 16, as square and seated in grooves 51 it is understood that I contemplate seating a wire of suitable shape on an ungrooved drum by suitable clamping means. The preferred clamping device comprises a plate 52 having a V-groove in its'lower surface and being perforated ,on both sides of the groove for the reception of cap-screws 53, 5 3 which are inserted through the perforations and screwed into threaded bores, formed in the surface of the. drum .15. "The'cap-screws 53, 53 are tightened so as to securely hold the wires from longitudinal movement.

Referring to Figs. 5 and 6, the trailing ends of the wires 16 are retained in place by similar clamping plates 54 and. capinterposed between their caps and the plate 54, resilient split washers 56, 56, whereby the having plate 54 is yieldingly urged against the wire the screws 55, 55 being tightened only sufficiently to maintain such yielding engagement of the plate with the wire and to permit longitudinal movement of the wire under the plate.

In operation," fabric 28, such as rubberized fabric to be cut on a bias, is trained over the rollers 25 and 27 and about the cutter, drum 15. The motor 24 is started by a suitable switch, notshown, and the fabric is carried between drum 15 and roll 29, the latter bein adjusted to press against the knives 16 with suflicient force to cut or pinch the material apart. The roller 39 serves to take up the spring in roller, 29 to maintain it against the knives throughout its length. The cut material is engaged by belt or liner 47 and is carried from the machine.

During the cutting action the roll 29, in effect, rolls on the knives l6 progressively from one end to the other, the leading end of the knife being held against longitudinal displacement due to this action but the trailing end of the knife being permitted to move longitudinally of itself under the re taining plate so as to prevent buckling of the knife. This action has been illustrated in Fig. 5, wherein the dotted line position of the end of wire 16 indicates the longitudinal play of the wire in the groove 51 due to the tendency of the material of the knife to he carried before the pressure or abutment rol By the above-described construction, breakage is reduced to a. minimum while replacements are made with great facility or scope thereof, as claimed in the appended claims.

' I claim: I

1. A rotary cutter comprising a drum and a. flexible knife secured at its leading end on the surface of the drum the remainder of the knife being so retained thereon as to permit longitudinal displacement thereof relatively to the drum surface.

2. A rotary cutter comprising a drum and a flexible knife helically mounted .about the of thedrum at its leading V having a groove therein, a flexible knife of the knife in the groove that longitudinal a flexible cutter wire, which has been hardened with a twist therein, seated on the surface of the drum.

6. A rotary cutter comprising a drum and a flexible cutter wire, which has. been hardened with a twist therein, seated on the drum, the leading end of said wire being secured to the drum, and the remainder of the wire being permitted to be longitudinally displaced.

7. A rotary cutter comprising in combination a drum, 'a flexible knife seated on said drum and secured thereon at its leading end, the trailing end of the knife being permitted to be longitudinally displaced, and means for pressing material against the knife.

8. A rotary cutter comprising in combination a drum, a flexible knife seated on said drum and secured thereon only at its leading end, the remainder of said knife being permitted to be' longitudinally displaced and a cooperating abutment roll for pressing material against the knife.

9. A rotary cutter comprising, in combination, a drum, a flexible knife seated on;

said drum and secured thereon only adjacent its leading end the remainder of said knife being permitted to be longitudinally displaced and a cooperating yieldingly mounted roller for pressing material against,

the knife.

10. A rotary cutter comprising a drum having a groove therein and a flexible knife seated in the groove and secured to the drum only at its leading rend.

11. A rotary cutter comprising a drum seated in the groove, means for securing the leading end of the knife in the groove and means for so retaining the trailing end displacement thereof in the permitted.

12. A rotary cutter comprising a drum having a groove therein, a flexible knife seated in the groove, means for securing groove will be wire being the leading end of the knife in the groove and yielding means for retaining the trailing end of the knife in the groove.

13. A rotary cutter comprising a drum having a groove therein, a flexible knife seated in the groove, means for securely clamping the leading end of the knife in Ia. twist therein, seated in the groove.

15. A rotary cuttercomprising a drum having a groove therein and a wire, set with a twist therein, seated in the groove, said secured only at its leading end to said drum.

16. A rotary cutter comprising a drum and a cutter held on the surface of said drum by torsional stresses therein.

17. The method of making a cutter drum comprising forming a cylinder, setting up torsional stresses in a cutter wire, and mounting the wire on the surface of the drum.

18. The method of making a cutter drum comprising forming a cylinder, twisting a cutter wire while soft, hardening the twisted wire, and wrapping the wire about the surface of the drum.

19. The method of making a cutter drum comprising. forming a cylinder with a groove therein, setting up torsional stresses in a cutter wire, and seating the wire in the groove. a

20. The method of making a cutter drum comprising forming a cylinder with a helical groove in the surface thereof, setting up torsional stresses in a cutter wire and seating the wire in the groove.

21. The method .of helically mounting a 

